By By: Chuck Goudie and Barb Markoff in Belize; Christine Tressel and Ross Weidner in Chicago

SAN IGNACIO, Belize (WLS) -- The United States now has federal agents on the scene in Belize to assist in the murder investigation of our ABC7 colleague Anne Swaney, as Belizean authorities say they are stepping up their efforts to solve the case, the ABC7 I-Team reports.

On the day Anne died, she walked down a path about a half a mile from the camp where she was staying. She came down to a wooden platform by the rushing river, where she put out her yoga mat. A police outline of the mat can still be seen on the deck, where police believe she was attacked. Her body was found in the water the next day, about 300 yards downriver. She had been strangled.

At the remote ranch in western Belize near the Guatemalan border, Juan walked the I-Team through Anne's last morning.

"She had breakfast and she had her coffee and she came to the stables that she normally greets the horses in the morning. And she was going to do her stretches, her yoga... Her intentions were to do her stretches, do her yoga, maybe get a ride in and buy some gifts in San Ignacio, the local town... because she was already halfway through her holiday and she wanted to bring gifts back to her loved ones," Juan said.

Juan and his stable hands have all been questioned numerous times by local authorities. A man was among several ranch employees at the police station Tuesday for another round of questioning.

Even though the FBI is offering assistance, the investigation is based out of the Benque Viejo branch of the Belize National Police.

On Tuesday, authorities here said they formed a task force of about 10 officers from across the country to try to solve the case.

Also, a Guatemalan national - arrested near Anne's murder scene and held on immigration charges - has still not been cleared in her killing. But some sources familiar with the investigation say authorities are leaning in another direction.

The I-Team has been told detectives have identified what is known here as a "person of concern" in connection with the case, believed to be a ranch worker.

The resort owner said Tuesday that only one thing matters: finding whoever is responsible.

"I would like to send my deepest condolences to her family and all of her loved ones wherever they may be," Juan said.

Authorities are still waiting on lab tests and say they may ask the FBI for help with more sophisticated forensic work.